The invention relates to a flow guiding system for a rotary combustion engine and a rotary combustion engine.
Thermal management—i.e. cooling and heating respectively—is very important in rotary combustion engines like e.g., aircraft turbines. Certain parts of the engine are e.g., subjected to very high temperatures. Further acting upon the engine are mechanical loads e.g., through the rotation of a compressor or a turbine. The structure of the engine needs to be maintained within design limits during operations.
One aspect in maintaining the design limits is the active control of the tip clearance i.e., the distance between the tips of the turbine blades and the surrounding walls. These systems are e.g., known as ATCC (active tip clearance control systems). The tip clearance is—among other parameters like the radial expansion of the blades—influenced by the cooling of the wall surrounding the blades. The cooling medium can be e.g., air taken from the bypass region (bypass duct) of the engine which is channeled into the core region of the engine and guided towards the wall to be cooled. Such a system is e.g., described in EP 2 224 099 A2.
By channeling cooling air in the engine other engine design parameters might be influenced e.g., the concentration of a fire extinguishing medium necessary in the engine in a fire event. The design parameters set a certain concentration of the fire extinguishing medium (e.g. Halon) to be reached and maintained in certain regions of the engine within tight time limits.